1. Field of the Invention
The present invention concerns a cooling device for power electronic components with particular application to semiconductor components.
2. Description of the Prior Art
It is standard practise to cool high-voltage and power electronic components using a coolant fluid. Various methods have been proposed.
The coolant fluid may be water, which has the advantages of being inexpensive and non-pollutant. In this case electrical insulation must be provided between the cooling water and the conductive parts of the component to be cooled. Document DE 4 017 749 discloses a cooling device for semiconductor components whose electrical contacts are in the form of two opposed parallel surfaces. The components are designed to be stacked and there are piled up in succession a first electrical connection, a first component, a second electrical connection, an electrically insulated body which is a good heat conductor and in which the water flows, a further first electrical connection, and so on. This device is particularly bulky. Also the electrically insulative and good heat conductor materials are less efficient in terms of heat exchange than a metal which is a good electrical conductor, such as copper.
Also known are direct cooling devices in which a heat and electrical conductor body is disposed directly on the electrical connection. The conductive body is connected to insulative tubes through which a dielectric cooling fluid is caused to flow in the body. The dielectric fluid may be oil or de-ionized water if an inexpensive non-polluting fluid is preferred. Oil has poor thermal performance in any event. As for de-ionized water, it requires a bulky and costly treatment system.
Another solution is to effect cooling by interposition of encapsulated insulative plates. In the case of superposed semiconductor components of the type mentioned above, the stacking is effected as follows: component, electrical connection, first copper weight, electrically insulative and heat conducting plate, second copper weight, metal cooling body in which flows a fluid such as water, and then the same components in reverse order: the two weights separated by the insulative plate, the electrical connection and the component. To increase the length of the electric field lines it is necessary to encapsulate the insulative plate between the two adjacent weights. This solution results in a very bulky device.
These various prior art solutions thus all have drawbacks that the present invention can remove. To this end the invention proposes a device integrating into a single system at least one electrical connection, one insulative plate per connection and a metal cooling body using non-de-ionized water.